Conventional methods for controlling vehicle positioning include anti-lock braking systems (ABS) control and vehicle stability control systems for preventing sideslip. Under ABS control, the wheels fitted to the vehicle are prevented from locking in the case of tire slip. This is achieved by controlling the braking force generated at each wheel so that the wheel speed conforms to a target wheel speed, thereby regulating a slip ratio. Vehicle stability control systems are designed to prevent oversteer or understeer of the vehicle. This is achieved by applying additional braking force to a target wheel or wheels to enable the vehicle to follow an ideal trajectory. Japanese Patent Laid-Open Publication No. Hei 11-20648 discloses one such system.
However, a conventional vehicle positioning control apparatus for ABS control or vehicle stability control or the like may be unable to cope with situations where a very sudden change in positioning causes the vehicle to spin such as the case of a blown tire. Therefore a vehicle positioning control system that is also able to control the positioning of the vehicle under these types of extreme situations would be very desirable.